Cholesteryl ester transfer protein gene polymorphisms increase the risk of fatty liver in females independent of adiposity

Background and Aim: Environmental factors including excessive caloric intake lead to disordered lipid metabolism and fatty liver disease (FLD). However, FLD demonstrates heritability suggesting genetic factors are also important. We aimed to use a candidate gene approach to examine the association between FLD and single nucleotide polymorphisms (SNPs) in lipid metabolism genes in the adolescent population‐based Western Australian Pregnancy (Raine) Cohort. Methods: A total 951 seventeen year‐olds underwent hepatic ultrasound, anthropometric and biochemical characterization, DNA extraction and genotyping for 57 SNPs in seven lipid metabolism genes (ApoB100, ATGL, ABHD5, MTTP, CETP, SREBP‐1c, PPARα). Associations were adjusted for metabolic factors and Bonferroni corrected. Results: The prevalence of FLD was 16.2% (11.4% male vs 21.2% female, P = 0.001). Multivariate analysis of metabolic factors found suprailiac skinfold thickness (SST) to be the major predictor of FLD in females and males (odds ratio [OR] 1.11, 95% confidence interval [CI] 1.08‐1.15, P = 1.7 × 10^?10 and OR 1.17, 95%CI 1.13–1.22, P = 2.4 × 10^?11, respectively). In females, two SNPs in linkage disequilibrium from the CETP gene were associated with FLD: rs12447924 (OR 2.16, 95%CI 1.42–3.32, P = 0.0003) and rs12597002 (OR = 2.22, 95%CI 1.46–3.41 P = 0.0002). In lean homozygotes, the probability of FLD was over 30%, compared with 10–15% in lean heterozygotes and 3–5% in lean wild‐types. However, these associations were modified by SST, such that for obese individuals, the probability of FLD was over 30% in all genotype groups. Conclusions: Cholesteryl ester transfer protein gene polymorphisms are associated with an increased risk of FLD in adolescent females. The effect is independent of adiposity in homozygotes, thereby placing lean individuals at a significant risk of FLD.     

大鼠、兔和人关节软骨组织形态学的比较

目的:观察比较大鼠、兔和人正常关节软骨组织学结构和关节炎软骨病理变化的差异。方法:实验于2006-08/2007-04在北京大学运动医学研究所完成。取大鼠、兔和人正常的关节滑车软骨和关节炎的滑车软骨,人关节软骨来源告知患者并征得同意,进行苏木精-伊红和甲苯胺蓝组织学染色,观察正常关节软骨的形态结构及关节炎软骨的病理变化。结果:关节软骨具有明显的分层,3者的主要区别在于软骨的第三层和潮线。大鼠软骨的第三层是典型的肥大细胞,无潮线;兔软骨的第三层是典型的柱状细胞层,潮线明显;人的软骨第三层为深层带,细胞较大,形态不规则,有多核细胞存在,有明显的潮线。正常软骨甲苯胺蓝染色均匀。关节炎软骨变化从表面开始,大鼠表现为表层软骨纤维样变,肥大细胞消失;兔和人表现为表层软骨细胞坏死,深层细胞排列紊乱。甲苯胺蓝染色失染或染色不均。结论:大鼠、兔和人的关节软骨结构不尽相同,主要差别在第三层和潮线的有无。关节炎软骨的变化也各有异同,但兔的软骨变化更接近于人。     

Activation of the contact system in insect-sting anaphylaxis: association with the development of angioedema and shock

A postulated role of the contact system in anaphylactic reactions to insect stings was investigated. During prospective, in-hospital sting challenge, we collected serial blood samples from five normal volunteers and 16 patients with a history of insect-sting anaphylaxis. Activation of the contact system was assessed by measuring plasma levels of factor XIIa-C1-inhibitor and kallikrein-C1-inhibitor complexes as well as those of cleaved high molecular weight kininogen (HK). In addition, antigenic levels of (pre)kallikrein, factor XII, and HK were measured. No significant changes in contact system parameters were observed in any of the five volunteers or the four patients who did not develop an anaphylactic reaction after sting challenge. In contrast, significant changes in contact system parameters occurred in 7 of the 12 patients with anaphylactic symptoms after challenge. Peak levels of either C1-inhibitor complex were found 5 minutes after the onset of anaphylactic symptoms. The increase in C1-inhibitor was most pronounced in the 4 patients with angioedema, 2 of which also developed shock. However, activation of HK was observed in all four patients with angioedema, the two patients with shock but no angioedema, as well as in 1 of the remaining 6 patients with anaphylactic symptoms other than angioedema or shock. Thus, activation products of the contact system may be involved in the pathogenesis of angioedema and shock in insect- sting anaphylaxis.     

The putative factor IX gene promoter in hemophilia B Leyden

Hemophilia B Leyden is characterized by low levels of factor IX antigen and activity before the age of 15, whereas after puberty factor IX levels rise at a rate of about 5% per year. A single base substitution (-A----T) at position -20 was identified in the putative promoter of the gene cloned from a patient with hemophilia B Leyden. This nucleotide change was confirmed in a second patient from the same pedigree and was also found in a patient from a second Dutch pedigree with the same hemophilic phenotype. The results indicate that the two Dutch kindreds are related and point to the functional significance of the -20 position for the expression of the human factor IX gene.     

Modulation of neutrophil oxidative responses to soluble stimuli by platelet-activating factor

The role of platelet activating factor (PAF) as a regulator of human neutrophil superoxide (O2-) generation in response to soluble and particulate stimuli was examined. At concentrations greater than 10(-7) mol/L, PAF alone induced a brief burst of O2- production. When cells were exposed to PAF and either the chemotactic peptide n-formyl- methionyl-leucyl-phenylalanine (FMLP 10(-7) mol/L) or the tumor promoter phorbol myristate acetate (PMA 10 ng/mL), a marked synergistic augmentation of O2- release was noted when compared to control cells stimulated with FMLP or PMA alone. Mean percentage of enhancement by 10(-5) mol/L of PAF was 297% +/- 35% (n = 9) of control responses to FMLP and 185% +/- 16% (n = 3) of control responses to PMA. Consistent enhancement occurred with PAF concentrations of as low as 10(-9) mol/L. Enhancement could be demonstrated when neutrophils were exposed to PAF either at the same time as, or up to 60 minutes prior to, the second stimulus, and was neither reversed by removal of PAF from the medium prior to addition of FMLP or PMA nor dependent on the presence of extracellular divalent cations. Continuous recordings revealed that the enhancement was due to an increased maximal rate of O2- production. In contrast, PAF concentrations up to 10(-5) mol/L had only a minimal effect on the response to neutrophils to opsonized zymosan. Analysis of the enhancing properties of lipids structurally related to PAF revealed that the critical moiety was the saturated fatty acid at position 1. These results indicate the presence of a PAF-mediated positive feedback loop whereby the oxidative burst induced by some soluble stimuli is augmented. Modulation of neutrophil O2- production by PAF may serve to amplify neutrophil oxidative responses at sites of inflammation.     

Lysis of human fibroblast colony-forming cells and endothelial cells by monoclonal antibody (6-19) and complement

The murine IgG2a monoclonal antibody 6-19 binds to a wide variety of nonhematopoietic cells including human marrow-derived stromal cells but does not bind to marrow or peripheral blood cells. We studied the effects of this antibody and rabbit complement on marrow cells. Fibroblast colonies were eliminated from light density marrow cells by a single incubation with monoclonal antibody 6-19 and complement. The growth and composition of granulocytic and erythroid colonies were unaffected. Specific complement mediated cytotoxicity of the antibody was confirmed on passaged human fibroblasts derived from marrow (more than 99.6% of fibroblasts are killed by a single treatment). Similar results were obtained with human umbilical cord endothelial cells. In addition, such treatment abolished the initiation of Dexter culture stroma. Incubation of bone marrow cell suspensions with this antibody and complement will allow the study of stroma-free marrow cells in long- term liquid cultures.     

A population-based study of the biochemical and clinical expression of the H63D hemochromatosis mutation

BACKGROUND & AIMS: Two major mutations are defined within the hemochromatosis gene, HFE. Although the effects of the C282Y mutation have been well characterized, the effects of the H63D mutation remain unclear. We accessed a well-defined population in Busselton, Australia, and determined the frequency of the H63D mutation and its influence on total body iron stores. METHODS: Serum transferrin saturation and ferritin levels were correlated with the H63D mutation in 2531 unrelated white subjects who did not possess the C282Y mutation. RESULTS: Sixty-two subjects (2.1%) were homozygous for the H63D mutation, 711 (23.6%) were heterozygous, and 1758 (58.4%) were wild-type for the H63D mutation. Serum transferrin saturation was significantly increased in male and female H63D homozygotes and heterozygotes compared with wild-types. Serum ferritin levels within each gender were not influenced by H63D genotypes. Elevated transferrin saturation > or = 45% was observed in a greater proportion of male H63D carriers than male wild-types. Male H63D homozygotes (9%) and heterozygotes (3%) were more likely to have both elevated transferrin saturation and elevated ferritin > or = 300 ng/mL than male wild-types (0.7%). Homozygosity for H63D was not associated with the development of clinically significant iron overload. CONCLUSIONS: Presence of the H63D mutation results in a significant increase in serum transferrin saturation but does not result in significant iron overload. In the absence of the C282Y mutation, the H63D mutation is not clinically significant.     

Rates of sustained virological response 12 weeks after the scheduled end of direct‐acting antiviral (DAA)‐based hepatitis C virus (HCV) therapy from the National German HCV registry: does HIV coinfection impair the response to DAA combination therapy?

Objectives

The European Association for the Study of the Liver (EASL) treatment recommendations for hepatitis C no longer discriminate between HIV/hepatitis C virus (HCV)‐coinfected and HCV‐monoinfected patients. However, recent data from Spain are questioning these recommendations on the basis of the findings of higher relapse rates and lower cure rates in HIV/HCV‐infected subjects. The aim of our study was to compare HCV cure rates in monoinfected and coinfected patients from Germany.

Methods

Data acquired from the Deutsches Hepatitis C‐Registry were analysed. A total of 5657 HCV‐monoinfected subjects and 488 HIV/HCV‐coinfected patients were included in the study. Rates of sustained virological response 12 weeks after the scheduled end of therapy (SVR12) were collected in both subgroups and in cirrhotic and noncirrhotic patients.

Results

HIV/HCV‐coinfected patients were more frequently male (84.6% vs. 56.4%, respectively; P < 0.001) and younger than HCV‐monoinfected subjects (46.5 ± 9 vs. 53.8 ± 12.5 years, respectively; P < 0.001). The CD4 blood cell count was > 350 cells/μL in 63.1% of HIV‐positive subjects and 88.7% were on antiretroviral therapy. SVR12 rates were 90.3% (5111 of 5657) in our HCV‐monoinfected cohort and 91.2% (445 of 488) in our coinfected patients. Liver cirrhosis was confirmed in 1667 of 5657 (29.5%) monoinfected patients and 84 of 488 (17.2%; P < 0.001) coinfected patients. SVR12 rates did not differ between HCV‐monoinfected and HIV/HCV‐coinfected patients with liver cirrhosis (87.8% vs. 89.3%, respectively; P = 0.864). A treatment duration of 8 weeks did not reduce the percentage of patients with SVR12 in either subgroup (93.7% in both groups).

Conclusions

We found high SVR12 rates in monoinfected as well as coinfected individuals. No differences were detected between the two subgroups regardless of whether there was accompanying liver cirrhosis or a shortened treatment duration.